The Overlap and Distinction of Self-Reported Symptoms between Interstitial Cystitis/Bladder Pain Syndrome and Overactive Bladder: A Questionnaire Based Analysis

Purpose: We compared symptoms between interstitial cystitis/bladder pain syndrome and overactive bladder based on patient self-reported symptoms on validated questionnaires. Materials and Methods: We prospectively recruited 26 patients diagnosed with interstitial cystitis/bladder pain syndrome, 53 diagnosed with overactive bladder and 30 healthy controls to participate in a questionnaire based study that inquired about lower urinary tract symptoms. The questionnaires used were GUPI, ICSI, ICPI, ICIQ-OAB, ICIQ-UI, IUSS, numerical rating scales of the severity of bladder pain, pressure or discomfort, and numerical rating scale of the severity of urgency and frequency symptoms. Results: On univariate analysis patients with interstitial cystitis/bladder pain syndrome reported significantly more severe pain symptoms than those with overactive bladder. Patients with overactive bladder reported significantly more severe urinary incontinence symptoms than those with interstitial cystitis/bladder pain syndrome. There was no difference in frequency and urgency severity between the groups. Surprisingly, 33% of patients with overactive bladder reported pain or discomfort when the bladder filled and 46% with interstitial cystitis/bladder pain syndrome reported urgency incontinence. On multivariate analysis ICIQ-UI total scores (p = 0.01) and bladder pain severity on the numerical rating scale (p < 0.01) distinguished the 2 conditions with 90.6% sensitivity and 96.1% specificity. Overactive bladder had higher ICIQ-UI and lower numerical rating scale pain scores. Conclusions: There is considerable overlap of self-reported symptoms between interstitial cystitis/bladder pain syndrome and overactive bladder. This overlap raises the possibility that the 2 conditions represent a continuum of a bladder hypersensitivity syndrome.